Electric-lighted level.



E.' G. LAPLANTE.

1511611110 UGHTED LivEL.

APPLICATION FILED OCT. 6, 1915.

1,176,374. Patented Mar. 21, 1916.

|i}R].\`l'ES'.l. GGDFREY LAPLANTE, OF MARLBORO, MASSACHUSETTS,

ELECTRIC-LIGHTED LEVEL.

Specification of Letters Patent.

Patented Mar. 21 1916.

Application led October 6, 1915. Serial No. 54,464.

To all lwhomfit may concern Be it known that I, ERNEST G. LAPLANTE, a citizen of the United States, residing at Marlboro, Massachusetts, have invented a new and useful Electrie-Lighted Level, of

which the following is a specication.

Among the important objects'of the invention are to illuminate both a horizontal and vertical level glass by one electric bulb; to provide one or more convenient switches or push buttons for controlling 'the light; to provide a lock for controlling the lamp circuit, and to provide new and useful construction andarrangement of parts as will hereinafter appear. y

The accompanying drawing shows one exeml'iliiication of the invention, but it is to be understood that the invention is capable ot embodiment in different forms. Figure 1 is a perspective view; Fig. 2 is a side elevation with the cover removed; Fig. 3 is a transverse section showing the push buttons and connections; F ig. a is a detail ot the lamp socket; Fig. 5 is a transverse section of the same; Fig. 6 is a transverse section of the lock switch or circuit breaker; Fig. 7 is a side elevation of same.

Reference character 1 designates a boxlike housing having a removable side plate or cover 2, secured by screws 3.' This housing has suitable top l'langes-4 for securing the housing to the wooden body of a level.

suitably located in the housing is an opening 5 defined by a curved tallo. This opening extends through the housing from side to side and communicating with it also is an aperture 7 in the top of the housing. l The curvature of the wall 6' provides forthe a1'- rangemcnt of two' level glasses 8 and 9 at right 'angles to each other so that the bubbles are observable. through opening 5 from either side or from Athe top of 'the level.

At oneside of theA opening 5, in the wall (3. is a small light aperture 10, at the rear ot' whichgis placed an electric bulb-11, usually cushioned against lheinner side of wall 6 by a suitably apertured piece of felt 1Q or other 4suitable cushioning device. The bulb is held by a clip or socket consisting of spring pieces 13 secured to an insulated base 14. The threaded part of,the-lnllb,'constitutiug one terminal, lnay be easily snapped into the socket o 'r clip in an' obvious-way. At some distance from the'Hwall 6 is partition 15. The dry celll of any suitable form for the purpose is removably placed in the housing between partition 15 and the bulb. There are standard cells for this purpose, among which is a cell having an insulating sleeve, an exposed base constituting one of the terminals of the cell, and at the opposite end a metallic piece 17 constituting the other terminal. The cell is held in place removably and electrically connected as follows:

A piece of insulating material 18 is placed against partition 15, and against this insulator is a helical spring 19 to which a conductor is connected. This helical spring makes electric contactl with the base terminal of the cell, and at the same time urges the cell against the base terminal of the lamp bulb so that electric connection is made with the lamp at 17. The spring pressure applied to the cell also assists in holding the lamp in, position against cushion 12. The cell is further supported laterally by transverse partitions 21 suitably recessed to accommodate the cell, and when cover 2 is in position, the cell is firmly held in its position until it is necessary to replace it.

Suitable controlling switches, usually in the form of push buttons 22, are .placed in the sides ot the housing and by suitable wiring 23, the appropriate terminals of the push buttons are connected with base terminal of the cell through wire Q0 and with a locked circuit breaking device through wire 24. lViring of the adjacent push buttons 22 is suliciently long to permit the cover Q to be removed without disturbing the wiring. At the opposite end of the housing upon a suitably insulated base 25 is a circuit breaker or main switch 26 consisting o't' two contact pieces 27 and Q8, usually made of spring metal. Back of contact Q8 is'insulating material 29, against which the end of the bolt 30 engages. The

bolt is controlled by the key operated lock 31 of which the key hole is seen at 3Q in Fig. 1 k When the key is suitably moved the bolt is extended to bringcontacts 27 and 2S-togethe1z`ainl the bulb may then be lighted by pressing either 'of the push buttons 2'2, and whenso lighted the opening 5 and both ot the level glasses are clearly illuminated, but with very little consumption of current, owing to the fact that a very small bulb inaV be employed. lVlien, however, it is desired to prevent the use of the lamp, the key is turned to retract bolt 30, and the battery circuit is then broken between contacts 27 and '28, and manipulation of the llt) push buttons will be inefectual to light the lamp.

Claim:

In a level, the combination of a liousin 5 having a ytransverse opening with a curve Wall, two level zglasses arranged in said opening at right angles to each other, said Wall having a lamp aperture, an electric bulb at said aperture to illuminate the glasses, a contact clip to lhold the bulb, a battery cell, spring means to 'urge one terminal of the cell into engagement With the base terminal of the bulb, said means also serving to make Contact with the other tei'- minal of the cell, and a push button in circuit between said sDring and said clip.

ERNEST GODFREY LAPLANTE. 

